Zoom Server checkpointing on restart

From 5.2 and above, Zoom server can be configured to perform database checkpointing only at scheduled automatic server restarts. Previously, every time Zoom server started, checkpointing would be performed. This checkpointing would take stock of all data operations executed on the Zoom server since the previous checkpoint, compacting the database in the process. However, this was inconvenient as the server became unavailable until checkpointing completed, especially at times when say, administrative setting changes require server restarts.

For Zoom versions before 5.2, checkpointing is enabled by default and is executed upon Zoom Server startup.

With, Zoom 5.2 and above, if the Zoom server has been scheduled to restart automatically at a particular time and frequency, say daily at 1 AM, then checkpointing is performed only on those scheduled server restarts. On all other restarts, the server will not perform checkpointing.

Automatic Checkpointing Service

The auto-restart can be configured using the Zoom Web Management Console. Log into Web Management Console as an admin. Go to Server Control Panel under System node in the Admin Menu on the left. Click Automatic Server Restart Settings.

If Enable Auto-Restart Service is checked, Zoom will follow the scheduled setup, such as every 7 days on Sunday midnight, to perform a server restart and a subsequent checkpoint. In order to do so, before every auto-restart, the <doCheckpoint> tag under <autorestartspec> in server.xml is automatically modified to true by the auto-restart service. Once the checkpoint is finished, the property is reset back to false in server.xml file.

If auto-restart is disabled, checkpoint will be enabled for each restart. Administrators can override this by setting <doCheckpoint> tag as false in server.xml to ensure that the server restarts without checkpointing. However, after a successful startup, the server will revert to performing checkpointing on subsequent restarts. This is necessary as periodic checkpointing needs to be performed automatically.

Forced or Manual Checkpointing

The administrator can enable or disable the automatic checkpointing with server restarts either by using javaZoom tool or by directly modifying server configuration file. Each method is explained below.

  • Using the javaZoom tool (recommended method). javaZoom is an utility available with Zoom, from version 5.3 and above.
    1. Open Terminal or Command-Prompt on the Zoom Server.
    2. Navigate to the bin directory (Linux: [ZoomInstallDir]/bin Windows: [ZoomInstallDir]\bin).
    3. To restart the Zoom server with checkpointing, run the command. Note: Zoom server won’t be accessible during the checkpointing. Make sure you perform the check pointing in a planned event.
      ./javaZoom checkpoint on
    4. To enable checkpointing for the next server restart, but without immediately restarting the server, run the command:
      ./javaZoom checkpoint on -nr
    5. To see javaZoom checkpoint utility’s usage help, run the command:
      ./javaZoom checkpoint help
    6. Ensure check pointing is finished by verifying the server log messages. See the below section: Verify the Performed Checkpointing

  • Manual edit and restart: (not recommended)
    1. On the Zoom Server, open the server configuration file, server.xml, from the installation conf directory (Linux: [ZoomInstallDir]/conf Windows: [ZoomInstallDir]\conf).
    2. Locate the tag doCheckpoint under <autorestartspec>. It governs if checkpointing will be performed on the next server start.
    3. Set the value of tag <doCheckpoint> to true.
    4. Save the file.
    5. Restart Zoom Server.

Verify the Performed Checkpointing

  • Always ensure that checkpointing has been completed by viewing the server_log.0 file under [ZoomInstallDir]/logs directory and confirming the following log record exists with the time-stamp. Look the Redo log checkpointing start and Redo log checkpointing ended.
    If the checkpoint is not performed, server will use the word: without checkpointing in the log messages. Please utmost pay attention to these messages.
INFO: Sun, 22 Nov 2015 20:06:55.527 PST [TransactionRedoLogManager.redoSecondPass Zoom Main Thread-1] Redo log checkpointing estimate: 450 kb in 0.00 s (at 15 mb/s).
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INFO: Sun, 22 Nov 2015 20:06:56.060 PST [TransactionRedoLogManager.setup Zoom Main Thread-1] Redo log checkpointing ended.

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